The primary reason for pitching this idea to SEGA JP to allow the release of information for content updates 2-4 weeks prior is to allow the newer playerbase to adjust to the incoming content before it arrives, especially considering the mixture of veteran/newer players.
The reason for needing this becomes reinforced even more when considering the PC users joining at the end of May. Some content will introduce superior alternatives to armor/weapons that may currently be available, but the newer players are not aware necessarily of what comes along with each UQ/Episode.
Example: Currently the Saiki set sells for a lot of meseta. Once Keys are available, the saiki will no longer be worth the huge prices. If a newer player were to buy a Saiki Back for 8 million the night before maintenance and suddenly wake up to discover they are now only worth 300K, it would be very discouraging.
The bottom line up front is that announcing the UQs/content at least 2 weeks before the maintenance that adds it to the game allows the community sherpa to prepare the newer players for that transition to mitigate the potential damage from the veteran players that want to exploit their lack of experience/knowledge.